Poles and masts of various types incorporating pivotally attached pole components are known. It is also known to use such poles and masts to support lights, the pivot feature utilized to replace, repair or otherwise service the lights supported thereby without the necessity of climbing.
Counter-weights have been employed to facilitate tilting of mast segments or portions; however, maintaining the tilted portion of a light apparatus at a stable and desired location can be difficult. As will be seen below, the subject invention provides a tilt control mechanism which frictionally engages a tiltable structure including a signal light relative to a base member and which releasably maintains the tiltable structure at alternative selected tilt orientations relative to the base member in the absence of outside forces of predetermined magnitude being applied to the tiltable structure. In other words, an individual can attain the desired degree of tilt and maintain the desired degree of tilt until exerting a force on the tiltable structure sufficient to return it to upright position or change the degree of inclination.
This keeps the individual, such as signal maintainer or inspector, on the ground instead of having to climb a ladder and work from a platform.
The following patent documents are believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 3,355,847, issued Dec. 5, 1967, U.S. Pat. No. 4,149,347, issued Apr. 17, 1979, U.S. Pat. No. 189,514, issued Apr. 10, 1877, U.S. Pat. No. 4,697,672, issued Oct. 6, 1987, U.S. Pat. No. 5,171,088, issued Dec. 15, 1992, U.S. Pat. No. 926,426, issued Jun. 29, 1909, U.S. Pat. No. 5,170,975, issued Dec. 15, 1992, U.S. Patent Publication No. US 2013/0220760, published Aug. 29, 2013, Patent Publication WO 2009/007757, published Jan. 15, 2009, French Patent No. FR2875582, issued Mar. 23, 2007, French Patent No. FR2924731, issued Jun. 12, 2009, Korean Patent No. KR101108665, issued Jan. 25, 2012, Chinese Patent No. CN2531042, issued Jan. 15, 2003.